Structure of poly(vinyl alcohol) hydrogel prepared by repeated freezing and melting

Abstract Investigations have been made into the relationship between rubber elasticity, state of water, and fine structure in poly(vinyl alcohol) (PVA) hydrogels prepared by repeated freezing and melting of aqueous solution. The elasticity of the hydrogel increases with increasing hydrogen bond interaction between water and the molecular sheet of the PVA crystallite crosslink points, and between water and the amorphous chain between crosslinks. The effect is not due to an increase in the number and size of the crystallites.